黄土高原退耕地生物土壤结皮广泛发育，在有效防止坡面土壤流失的同时显著降低了土壤水分入渗，使退耕地形成“保土不保水”的水土流失格局，恶化了土壤水分状况。针对黄土高原水土流失防治需求与生物结皮“保土不保水”功能矛盾的现实问题，基于干扰理论，通过野外小区定位监测，利用自然降雨，研究干扰对生物结皮微生态系统结构（生物群落结构、结皮形态结构、土壤物质组成）及水土保持功能（渗透性、可蚀性及径流量、泥沙量）的影响，借助结构方程模型解析干扰条件下生物结皮微生态系统结构与水土保持功能间的耦合互馈机理，明确适度干扰协同生物结皮“保土不保水”矛盾的可能性，建立不同季节干扰度与水土保持功能指标间的量化关系，确定适宜的干扰季节及干扰度，提出生物结皮水土保持功能的协同方案，趋利除弊，为区域水土流失防治及退耕地的科学管理提供依据。对明确生态系统结构-功能耦合机理及适度干扰协同生态系统功能矛盾的可能性有科学价值。

Biological soil crusts are widely developed in the hilly Loess Plateau, which effectively prevent soil erosion from sloping land. However, the crusts also significantly reduce soil water infiltration, thus resulted a new pattern of soil erosion as "keep soil but loss water" with a worsen soil moisture conditions in the sloping land. To meet the demand of regional soil and water conservation and to overcome the reality issue of the contradictory function of biological crusts, the program was proposed based on the disturbance theory. Through located field plots monitoring under natural rainfall condition, the response of the micro-ecosystem structure of biological soil crusts (including biological community structure, morphology of biological soil crust and soil physicochemical composition, etc.), and soil and water conservation functions (i.e., rainfall permeability, erodibility and runoff, sediment) was investigated. The coupling and synergy mechanism between the micro ecosystem structure and soil-water conservation function of the biological crusts will be revealed based on the structural equation modeling. After understanding the possibility of synergizing the function contradictory through moderately disturbance, a quantitative relationship between disturbance and soil and water conservation function parameters will be established. In the view of “pursuing benefit and reducing defect", a program for synergizing the function contradictory through moderately disturbance will be proposed with the appropriate season and the corresponding degree of disturbance. The research results could provide a scientific basis for regional soil and water conservation as well as sustainable management of revegetated grassland. Meanwhile, the research could clear the coupling mechanism of ecosystem structure - function, and explore the possibility of synergizing the function contradictory through moderately disturbance.